On the one hand we have push-broom sensors, which restrict the light throughput of the objective of the camera by a micrometer-thin slit. On the other hand we see tunable filter devices, which only transmit a few nm of the full incident spectra onto the sensor. In either way, most of the incident light is blocked geometrically or is filtered out.
Snapshot imaging systems transmit the full spectrum of the light for the full image size. Thus, these kind of spectrometers capture a three dimensional dataset [x, y, lambda] in one sensor readout.
By this definition, Cubert GmbH is the only commercial source for hyperspectral snapshot cameras worldwide.